Partial Volume Correction Using Continuous Wavelet Technique in Small Animal PET Imaging

The underestimation of the emitted radioactivity in small tissue structures measured with PET unfortunately requires correction for the partial volume effect (PVE) prior to image analysis. Meanwhile, the continuous wavelet transform (CWT) has the potential to isolate the signal of small structures from their environments, and to determine each structure by its width and position in PET images. Using CWT analysis and recovery coefficients (RC), we report a new approach to correct for PVE in phantom and in rat PET images, regardless of the shape of the structures. The results show a full recovery in image intensity in the phantom small hot spots, and similarly in the rat tumors without any additional noise. On the other hand, dynamic FDG-PET was performed in rat images before and after PVE correction to assess tumor metabolic rates of glucose (MRG). The MRG values after PVE correction were significantly increased by 2.2 and 2.1 mu moles/100g/min for right and left tumors respectively, compared to those before PVE correction.